Fungicidal mixture

ABSTRACT

A fungicidal mixture comprisesa) a phenyl benzyl ether derivative of the formula I [sic]andb) (±)-(2-chlorophenyl)(4-chlorophenyl)(pyrimidin-5-yl)methanolin a synergistically effective amount.

This application is a 371 of PCT/EP98/02915, filed May 18, 1998.

The present invention relates to a fungicidal mixture which comprises

a) a phenyl benzyl ether derivative of the formula I.a or I.b

and

b) (±)-(2-chlorophenyl)(4-chlorophenyl)(pyrimidin-5-yl)methanol

in a synergistically effective amount.

Moreover, the invention relates to methods for controlling harmful fungiusing mixtures of the compounds I (I.a and I.b) and II and to the use ofthe compounds I and II for the preparation of such mixtures.

The compounds I, their preparation and their activity against harmfulfungi are disclosed in the literature (EP-A 253 213, EP-A 254 426).

Also disclosed is the compound II (GB-A 1,218,623; common name:Fenarimol), its preparation and its activity against harmful fungi.

It is an object of the present invention to provide mixtures which havean improved activity against harmful fungi combined with a reduced totalamount of active ingredients applied (synergistic mixtures), with a viewto reducing the application rates and to improving the activity spectrumof the known compounds.

We have found that this object is achieved by the mixture defined at theoutset. Moreover, we have found that better control of harmful fungi ispossible by applying the compound I and the compound II simultaneously,either together or separately, or by applying the compound I and thecompounds II in succession then when the individual compounds are usedon their own.

Owing to their basic character, the compounds I and the compound II arecapable of forming salts or adducts with inorganic or organic acids orwith metal ions.

Examples of inorganic acids are hydrohalic acids such as hydrofluoricacid, hydrochloric acid, hydrobromic acid and hydriodic acid, andfurthermore sulfuric acid, phosphoric acid and nitric acid.

Suitable organic acids are, for example, formic acid and alkanoic acids,such as acetic acid, trifluoroacetic acid, trichloroacetic acid andpropionic acid, and also glycolic acid, thiocyanic acid, lactic acid,succinic acid, citric acid, benzoic acid, cinnamic acid, oxalic acid,alkylsulfonic acids (sulfonic acids having straight-chain or branchedalkyl radicals of 1 to 20 carbon atoms), arylsulfonic acids oraryldisulfonic acids (aromatic radicals, such as phenyl and naphthyl,which carry one or two sulfo groups), alkylphosphonic acids (phosphonicacids having straight-chain or branched alkyl radicals of 1 to 20 carbonatoms), arylphosphonic acids or aryldiphosphonic acids (aromaticradicals, such as phenyl and naphthyl, which carry one or two phosphonicacid radicals), it being possible for the alkyl or aryl radicals tocarry further substituents, eg. p-toluenesulfonic acid, salicylic acid,p-aminosalicylic acid, 2-phenoxybenzoic acid, 2-acetoxybenzoic acid,etc.

Suitable metal ions are, in particular, the ions of the elements of thesecond main group, in particular calcium and magnesium, of the third andfourth main group, in particular aluminum, tin and lead, and of thefirst to eighth sub-group, in particular chromium, manganese, iron,cobalt, nickel, copper, zinc and others. Particular preference is givento the metal ions of the elements of the sub-groups of the fourthperiod. The metals can exist in the various valences which they canassume.

When preparing the mixtures, it is preferred to employ pure activeingredients I and II, to which further active ingredients againstharmful fungi of other pests, such as insects, arachnids or nematodes,or else herbicidal or growth-regulating active ingredients orfertilizers can be admixed, if so required.

The mixtures of compounds I and II, or the simultaneous joint orseparate use of the compounds I and II, exhibit outstanding activityagainst a wide range of phytopathogenic fungi, in particular from theclasses of the Ascomycetes, Basidiomycetes, Phycomycetes andDeuteromycetes. Some of them act systemically and can therefore beemployed as foliar and soil-acting fungicides.

They are especially important for controlling a large number of fungi ina variety of crop plants, such as cotton, vegetable species (e.g.cucumbers, beans, tomatoes, potatoes and cucurbits), barley, grass,oats, bananas, coffee, maize, fruit species, rice, rye, soya, grapevine,wheat, ornamentals, sugar cane, and a variety of seeds.

They are particularly suitable for controlling the followingphytophathogenic fungi: Erysiphe graminis (powdery mildew) on cereals,Erysiphe cichoracearum and Sphaerotheca fuliginea in cucurbits,Podosphaera leucotricha in apples, Uncinula necator in grapevines,Puccinia species in cereals, Rhizoctonia species in cotton, rice andlawns, Ustilago species in cereals and sugarcane, Venturia inaequalis(scab) in apples, Helminthosporium species in cereals, Septoria nodorumin wheat, Botrytis cinerea (gray mold) in strawberries, vegetables,ornamentals and grapevines, Cercospora arachidicola in ground nuts,Pseudocercosporella herpotrichoides in wheat and barley, Pyriculariaoryzae in rice, Phytophthora infestans in potatoes and tomatoes,Plasmopara viticola in grapevines, Pseudocercosporella species in hopsand cucumbers, Alternaria species in vegetables and fruit,Mycosphaerella species in bananas and Fusarium and Verticillium species.

Furthermore, it can be used in the production of materials (e.g. in theprotection of wood), for example against Paecilomyces variotii.

The compounds I and II can be applied simultaneously, either together orseparately, or in succession, the sequence, in the case of separateapplication, generally not having any effect on the result of thecontrol measures.

The compounds I and II are usually used in a weight ratio of 10:1 to0.1:1, preferably 5:1 to 0.2:1, in particular 3:1 to 0.3:1.

Depending on the kind of effect desired, the application rates of themixtures according to the invention are, in particular in agriculturalcrops, from 0.01 to 8 kg/ha, preferably 0.1 to 5 kg/ha, in particular0.2 to 3.0 kg/ha.

The application rates of the compounds I are from 0.005 to 0.5 kg/ha,preferably 0.05 to 0.5 kg/ha, in particular 0.05 to 0.3 kg/ha.

Correspondingly, in the case of compounds II, the application rates arefrom 0.05 to 0.5 kg/ha, preferably 0.1 to 0.5 kg/ha, in particular 0.1to 0.3 kg/ha.

For seed treatment, the application rates of mixture are generally from0.001 to 250 g/kg of seed, preferably 0.01 to 100 g/kg, in particular0.01 to 50 g/kg.

If phytopathogenic harmful fungi are to be controlled, the separate orjoint application of the compounds I and II or of the mixtures of thecompounds I and II is effected by spraying or dusting the seeds, theplants or the soils before or after sowing of the plants, or before orafter plant emergence.

The fungicidal synergistic mixtures according to the invention, or thecompounds I and II, can be formulated for example in the form ofready-to-spray solutions, powders and suspensions or in the form ofhighly concentrated aqueous, oily or other suspensions, dispersions,emulsions, oil dispersions, pastes, dusts, materials for broadcasting orgranules, and applied by spraying, atomizing, dusting, broadcasting orwatering. The use form depends on the intended purpose; in any case, itshould guarantee as fine and uniform as possible a distribution of themixture according to the invention.

The formulations are prepared in a manner known per se, e.g. by addingsolvents and/or carriers. It is usual to admix inert additives, such asemulsifiers or dispersants, with the formulations.

Suitable surfactants are the alkali metal salts, alkaline earth metalsalts and ammonium salts of aromatic sulfonic acids, eg. ligno-,phenol-, naphthalene- and dibutylnaphthalenesulfonic acid, and of fattyacids, alkyl- and alkylarylsulfonates, alkyl, lauryl ether and fattyalcohol sulfates, and salts of sulfated hexa-, hepta- and octadecanols,or of fatty alcohol glycol ethers, condensates of sulfonated naphthaleneand its derivatives with formaldehyde, condensates of naphthalene or ofthe naphthalenesulfonic acids with phenol and formaldehyde,polyoxyethylene octylphenol ether, ethoxylated isooctyl-, octyl- ornonylphenol, alkylphenol polyglycol ethers or tributylphenyl polyglycolethers, alkylaryl polyether alcohols, isotridecyl alcohol, fattyalcohol/ethylene oxide condensates, ethoxylated castor oil,polyoxyethylene alkyl ether or polyoxypropylene alkyl ethers, laurylalcohol polyglycol ether acetate, sorbitol esters, lignosulfite wasteliquors or methylcellulose.

Powders, materials for broadcasting and dusts can be prepared by mixingor joint grinding of the compounds I or II or the mixture of thecompounds I and II with a solid carrier.

Granules (e.g. coated granules, impregnated granules or homogeneousgranules) are usually prepared by binding the active ingredient, oractive ingredients, to a solid carrier.

Fillers or solid carriers are, for example, mineral earths, such assilica, silica gels, silicates, talc, kaolin, limestone, lime, chalk,bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate,magnesium sulfate, magnesium oxide, ground synthetic materials, andfertilizers, such as ammonium sulfate, ammonium phosphate, ammoniumnitrate, ureas, and products of vegetable origin, such as cereal meal,tree bark meal, wood meal and nutshell meal, cellulose powders or othersolid carriers.

The formulations generally comprise from 0.1 to 95% by weight,preferably 0.5 to 90 % by weight, of one of the compounds I or II or ofthe mixture of the compounds I and II. The active ingredients areemployed in a purity of from 90% to 100%, preferably 95% to 100%(according to NMR spectrum or HPLC).

The compounds I or II, or the mixtures, or the correspondingformulations, are applied by treating the harmful fungi, their habitat,or the plants, seeds, soils, areas, materials or spaces to be kept freefrom them with a fungicidally active amount of the mixture, or of thecompounds I and II in the case of separate application.

Application can be effected before or after infection by the harmfulfungi.

USE EXAMPLE

The synergistic activity of the mixtures according to the invention wasdemonstrated by the following experiments:

The active ingredients, separately or together, were formulated as a 10%emulsion in a mixture of 63% by weight of cyclohexanone and 27% byweight of emulsifier, and diluted with water to a desired concentration.

Use Example 1 Activity Against Puccinia recondite on Wheat (Wheat LeafRust)

Leaves of potted wheat seedlings of the variety “Frühgold” were dustedwith spores of the wheat leaf rust (Puccinia recondita). Thereafter, thepots were kept in a chamber of high atmospheric humidity (90 to 95%) and20 to 22° C. for 24 hours. During this time, the spores germinated andthe germ tubes penetrated into the leaf tissue. The next day, theinfected plants were sprayed to runoff point with an aqueous preparationof active ingredient which had been prepared from a stock solutioncomprising 10% of active compound, 63% of cyclohexanone and 27% ofemulsifier.

After the spraycoating had dried on, the test plants were cultivated for7 days in a greenhouse at 20-22° C. and 65-70% relative atmospherichumidity. Thereafter, the extent of the rust fungus development on theleaves was determined.

Evaluation was carried out by determining the infected leaf areas inpercent. These percentages were converted into efficacies. The efficacy(E) was calculated as follows using Abbot's formula:

E=(1−α)·100/β

α corresponds to the fungal infection of the treated plants in % and

β corresponds to the fungal infection of the untreated (control) plantsin %

An efficacy of 0 means that the infection level of the treated plantscorresponds to that of the untreated control plants; an efficacy of 100means that the treated plants were not infected.

The expected efficacies of the mixtures of the active ingredients weredetermined using Colby's formula [R. S. Colby, Weeds 15, 20-22 (1967)]and compared with the observed efficacies.

Colby's formula: E=x+y−x·y/100

E expected efficacy, expressed in % of the untreated control, when usingthe mixture of the active ingredients A and B at the concentrations aand b

x efficacy, expressed in % of the untreated control, when using activeingredient A at a concentration of a

y efficacy, expressed in % of the untreated control, when using activeingredient B at a concentration of b

The results are shown in Tables 2 and 3 below.

TABLE 2 Concentration of active ingredient Efficacy in % of in the spraythe untreated Ex. Active ingredient liquor in ppm control 1 C Control(100% infection) 0 (untreated) 2 C Ia 200 20 100 20 50 0 3 C II 20 0 100

TABLE 3 Mixtures according to Observed Calculated Ex. the inventionefficacy efficacy*) 4 200 ppm Ia 65 20 + 20 ppm II (mixture 10:1) 5 100ppm Ia 70 20 + 20 ppm II (mixture 5:1) 6 50 ppm Ia 35  0 + 10 ppm Ib(mixture 5:1) *)calculated using Colby's formula

The test results show that the observed efficacy in all mixing ratios ishigher than the efficacy which had been calculated beforehand usingColby's formula.

We claim:
 1. A fungicidal composition comprising a) as component I aphenyl benzyl ether of formula I.a or I.b

and b) as component II(±)-(2-chlorophenyl)(4-chlorophenyl)(pyrimidin-5-yl)methanol

in synergistically effective amounts.
 2. The composition defined inclaim 1, comprising component I and component II in a weight ratio offrom 10:1 to 0.1:1.
 3. A process for preparing the composition definedin claim 1, which comprises admixing synergistically effective amountsof component I and component II.
 4. The process of claim 3, whichfurther comprises admixing the components I and II with at least onesolid or liquid carrier.
 5. The composition defined in claim 1 which isconditioned in two parts, one part comprising component I in a solid orliquid carrier, and the other part comprising component II in a solid orliquid carrier.
 6. A method for controlling harmful fungi, whichcomprises treating the harmful fungi, their habitat, or plants, seeds,soils, areas, materials or spaces to be kept free from said fungi withsynergistically effective amounts of component I and component II,wherein components I and II are as set forth in claim
 1. 7. The methodof claim 6, wherein the components I and II are applied simultaneously,that is either together or separately, or in succession.
 8. The methodof claim 6, wherein the component I is applied in an amount of from0.005 to 0.5 kg/ha.
 9. The method of claim 6, wherein the component IIis applied in an amount of from 0.05 to 0.5 kg/ha.